(19)
(11) EP 0 508 459 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
13.01.1993 Bulletin 1993/02

(43) Date of publication A2:
14.10.1992 Bulletin 1992/42

(21) Application number: 92106251.9

(22) Date of filing: 10.04.1992
(51) International Patent Classification (IPC)5H04N 17/00
(84) Designated Contracting States:
DE FR GB

(30) Priority: 11.04.1991 JP 79013/91

(71) Applicant: SONY CORPORATION
Tokyo 141 (JP)

(72) Inventor:
  • Eguchi, Takeo
    Shinagawa-ku, Tokyo (JP)

(74) Representative: Körber, Wolfhart, Dr.rer.nat. et al
Patentanwälte Mitscherlich & Partner, Postfach 33 06 09
80066 München
80066 München (DE)


(56) References cited: : 
   
       


    (54) Digital transmission test system


    (57) Disclosed is a digital transmission test signal generating circuit for generating a digital test signal applied to a digital signal transmission system having encoding means (4), a transmission path (5), decoding means (7) and a display (9) supplied with the output of the decoding means (7). The digital transmission test signal generating circuit comprises generating means and timing means. The generating means generates repeatedly specific data with a predetermined bit pattern. The timing means controls the generating means in such a manner that the data will occur in the duration corresponding to a predetermined area of the display (9). The specific data generated constitute the worst-case state for the target transmission system to operate in. This provides easy, visual checks on the system to see on a monitor if it functions normally given the worst-case signals to work with. No specialized measuring instruments are required for the checks.







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